Organic Light Emitting Diode (OLED) display panels have gradually attracted the attention of people due to characteristics such as wide viewing angle, high contrast, fast response compared with conventional display panels, and advantages such as higher luminance, lower driving voltage and the like compared with inorganic light emitting diode display devices. Because of the above-mentioned characteristics, the organic light emitting diode (OLED) display panels can be applied into mobile phones, displays, laptops, digital cameras, instruments, and any devices with display functions.